Switching off interventional imaging systems could save providers tens of thousands annually, while helping them achieve sustainability initiatives by curbing their carbon footprint and energy consumption.

In a new study out of the radiology department at Switzerland's University Hospital Basel, researchers compared operational uses of equipment in an interventional radiology suite, a neuro-interventional suite, a radiology fluoroscopy unit, two cardiology laboratories, and two urology fluoroscopy units. Using various sources to determine power statuses, procedural time stamps, and fluoroscopy times, they looked at these systems when they were off, idle (no patient in the room), active (patient in the room for procedure), and in net-imaging (active fluoroscopic image acquisition) states.

With hypothetical operational adjustments, the researchers said that switching all these systems from idle to off overnight and on weekends, instead of running them 24/7, would save $37,896 per year and reduce energy consumption by 144,640 kilowatts per hour (kWh) and carbon emissions by 18.6 million tons of carbon dioxide equivalent (MtCO2eq). Their findings challenge the standard practice of using manufacturer-provided specifications to estimate the energy demand of interventional imaging systems instead of directly measuring it.
“Interventional imaging systems are energy intensive, with high consumption outside of image acquisition periods,” said AJR investigator Dr. Jan Vosshenrich, from the radiology department of the University Hospital Basel, in a statement. “Strategic operational adjustments (e.g., powering down idle systems) can substantially decrease interventional imaging systems’ carbon emissions and electricity costs.”

Results were based on power measurement logs for a single four-week period for each radiology and cardiology system and a two-week period for each urology system. The mean power draw among all seven was 0.3-1.1 kW, 0.7-7.4 kW, 0.9-7.6 kW, and 1.9-12.5 kW in off, idle, active, and net-imaging states, respectively.

When off, the mean power draw dropped from 22.2% to 93.2% to 02.-6.9 kW, compared to the idle state, for all systems. The combined projected annual energy consumption was 115,684 kWh (3,646 to 26,576 kWh per system). The combined projected energy consumption outside of the net-imaging state accounted for 93% (107,978/115,684 kWh) of projected total energy consumption, which ranged from 89.2% to 99.4% per system.

Medtech companies and providers are making sustainable, eco-friendly imaging a greater focus of their operations. Philips and Vanderbilt University Medical Center have partnered to develop computational simulations that show ways to reduce carbon dioxide emissions from the use of medical scanners as well as the total cost of ownership for these devices.

Siemens Healthineers also developed the first carbon-neutral radiology service at the University of California, San Francisco by using its Smart infrastructure solutions to monitor power consumption of its MR scanners there. It also developed a “power save” mode feature that decreases power usage by an additional 22% to 28% compared to off mode.

The findings were published in the American Journal of Roentgenology (AJR).

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